IC-NRLF 


SB    7b    IbE 


GIFT  OF 


Standard 
Specifications  and  Tests 


for 


Portland  Cement 

of  the 
American  Society  for  Testing  Materials 

Affiliated  with  the 

International  Association  for  Testing  Materials 
Philadelphia,  Pa. 


These  specifications  are  the  result  of  several  years' 
work  of  a  special  committee  representing  a  United  States 
Government  Departmental  Committee,  the  Board  of 
Direction  of  the  American  Society  of  Civil  Engineers, 
and  Committee  C-l  on  Cement  of  the  American  Society 
for  Testing  Materials,  in  cooperation  with  Committee  C-l. 


"Concrete    for    Permanence" 


Reprinted  by 

Portland  Cement  Association 


ATLANTA 

Hurt  Building 
INDIANAPOLIS 

Merchants  Bank  Building 
PABKERSBUBG,  W.  VA. 

Union  Trust  Building 


DECEMBER.    1916 


Offices  at 

CHICAGO  DALLAS 

111  W.  Washington  Street        Southwestern  Life  Building 
KANSAS  CITY  NEW  YORK 

Commerce  Building 
PITTSBURGH 


Farmers  Bank  Building 


101  Park  Avenue 
SAN  FRANCISCO 

116  New  Montgomery  Street 


Authorized  Reprint  from  the  Copyrighted 

A.S.T.M.  STANDARDS  (1916) 

AMERICAN  SOCIETY  FOB  TESTING  MATERIALS, 

PHILADELPHIA,  PA. 

STANDARD   SPECIFICATIONS  AND  TESTS  FOR 
PORTLAND   CEMENT.1 

Serial  Designation:  C  £-17. 

Definition.  1.  Portland  cement  is  the  product  obtained  by  finely  pul- 

verizing clinker  produced  by  calcining  to  incipient  fusion  an 
intimate  and  properly  proportioned  mixture  of  argillaceous  and 
calcareous  materials,  with  no  additions  subsequent  to  calcina- 
tion excepting  water  and  calcined  or  uncalcined  gypsum. 

I.  CHEMICAL  PROPERTIES. 
Chemical                    2.  The  following  limits  shall  not  be  exceeded: 

Limits. 

Loss  on  ignition,  per  cent 4 . 00 

Insoluble  residue,  per  cent 0 . 85 

Sulfuric  anhydride  (SO3),  per  cent 2 . 00 

Magnesia  (MgO),  per  cent 5 . 00 

II.  PHYSICAL  PROPERTIES. 

Specific  Gravity.  x  3.  The  specific  gravity  of  cement  shall  be  not  less  than 
3.10  (3.07  for  white  Portland  cement).  Should  the  test  of 
cement  as  received  fall  below  this  requirement  a  second  test  may 
be  made  upon  an  ignited  sample.  The  specific  gravity  test  will 
not  be  made  unless  specifically  ordered. 

Fineness.  4.  The  residue  on  a  standard  No.  200  sieve  shall  not  exceed 

22  per  cent  by  weight. 

Soundness.  5.  A  pat  of  neat  cement  shall  remain  firm  and  hard,  and 

show  no  signs  of  distortion,  cracking,  checking,  or  disintegration 
in  the  steam  test  for  soundness. 

Time  of  Setting.  6.  The  cement  shall  not  develop  initial  set  in  less  than  45 
minutes  when  the  Vicat  needle  is  used  or  60  minutes  when  the 
Gillmore  needle  is  used.  Final  set  shall  be  attained  within  10 
hours. 

Tensile  strength.  7.  The  average  tensile  strength  in  pounds  per  square  inch 
of  not  less  than  three  standard  mortar  briquettes  (see  Section  5 1) 

1  These  specifications  and  tests  were  adopted  by  letter  ballot  of  the  Society  on  September 
1,  1916,  with  the  understanding  that  they  will  not  become  effective  till  January  1,  1917. 

(2) 


SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT.      3 

composed  of  one  part  cement  and  three  parts  standard  sand,  by 
weight,  shall  be  equal  to  or  higher  than  the  following: 


Age  at  Test, 
days. 

Storage  of  Briquettes. 

Tensile  Strength. 
Ib.  per  sq.  in. 

7 

200 

28 

300 

8.  The  average  tensile  strength  of  standard  mortar  at  28 
days  shall  be  higher  than  the  strength  at  7  days. 

III.     PACKAGES,   MARKING  AND   STORAGE. 

9.  The  cement  shall  be  delivered  in  suitable  bags  or  barrels  Packages  and 
with  the  brand  and  name  of  the  manufacturer  plainly  marked 
thereon,  unless  shipped  in  bulk.    A  bag  shall  contain  94  Ib.  net. 

A  barrel  shall  contain  376  Ib.  net. 

10.  The  cement  shall  be  stored  in  such  a  manner  as  to  per-  storage, 
mit  easy  access  for  proper  inspection  and  identification  of  each 
shipment,  and  in  a  suitable  weather-tight  building  which  will 
protect  the  cement  from  dampness. 

IV.     INSPECTION. 

11.  Every  facility  shall  be  provided  the  purchaser  for  care-  inspection, 
ful  sampling  and  inspection  at  either  the  mill  or  at  the  site  of 

the  work,  as  may  be  specified  by  the  purchaser.  At  least  10 
days  from  the  time  of  sampling  shall  be  allowed  for  the  com- 
pletion of  the  7-day  test,  and  at  least  31  days  shall  be  allowed 
for  the  completion  of  the  28-day  test.  The  cement  shall  be 
tested  in  accordance  with  the  methods  hereinafter  prescribed. 
The  28-day  test  shall  be  waived  only  when  specifically  so  ordered. 

V.    REJECTION. 

12.  The  cement  may  be  rejected  if  it  fails  to  meet  any  of  Rejection, 
the  requirements  of  these  specifications. 

13.  Cement  shall  not  be  rejected  on  account  of  failure  to 
meet  the  fineness  requirement  if  upon  retest  after  drying  at 
100°  C.  for  one  hour  it  meets  this  requirement. 

14.  Cement  failing  to  meet  the  test  for  soundness  in  steam* 


347146 


SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT. 


Number  of 
Samples. 


Method  of 
Sampling. 


Treatment  of 
Sample. 


may  be  accepted  if  it  passes  a  retest  using  a  new  sample  at  any 
time  within  28  days  thereafter. 

15.  Packages  varying  more  than  5  per  cent  from  the  speci- 
fied weight  may  be  rejected;  and  if  the  average  weight  of  pack- 
ages in  any  shipment,  as  shown  by  weighing  50  packages  taken 
at  random,  is  less  than  that  specified,  the  entire  shipment  may 
be  rejected. 

TESTS. 

VI.     SAMPLING. 

16.  Tests  may  be  made  on  individual  or  composite  samples 
as  may  be  ordered.     Each  test  sample  should  weigh  at  least 
8lb. 

17.  (a)  Individual  Sample.— If  sampled  in   cars  one   test 
sample  shall  be  taken  from  each  50  bbl.  or  fraction  thereof. 
If  sampled  in  bins  one  sample  shall  be  taken  from  each  100  bbl. 

(b)  Composite  Sample. — If  sampled  in  cars  one  sample 
shall  be  taken  from  one  sack  in  each  40  sacks  (or  1  bbl.  in  each 
10  bbl.)  and  combined  to  form  one  test  sample.  If  sampled  in 
bins  or  warehouses  one  test  sample  shall  represent  not  more 
than  200  bbl. 

18.  Cement  may  be  sampled  at  the  mill  by  any  of  the 
following  methods  that  may  be  practicable,  as  ordered: 

,  (a)  From  the  Conveyor  Delivering  to  the  Bin.— At  least  8  Ib. 
of  cement  shall  be  taken  from  approximately  each  100  bbl. 
passing  over  the  conveyor. 

(b)  From  Filled  Bins  by  Means  of  Proper  Sampling  Tubes. — 
Tubes  inserted  vertically  may  be  used  for  sampling  cement  to 
a  maximum  depth  of  10  ft.     Tubes  inserted  horizontally  may  be 
used  where  the  construction  of  the  bin  permits.     Samples  shall 
be  taken  from  points  well  distributed  over  the  face  of  the  bin. 

(c)  From  Filled  Bins   at  Points   of  Discharge. — Sufficient 
cement  shall  be  drawn  from  the  discharge  openings  to  obtain 
samples  representative  of  the  cement  contained  in  the  bin,  as 
determined  by  the  appearance  at  the  discharge  openings  of 
indicators  placed  on  the  surface  of  the  cement  directly  above 
these  openings  before  drawing  of  the  cement  is  started. 

19.  Samples  preferably  shall  be  shipped  and  stored  in  air- 
tight containers.      Samples  shall  be  passed   through  a  sieve 


SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT.       5 

having  20  meshes  per  linear  inch  in  order  to  thoroughly  mix  the 
sample,  break  up  lumps  and  remove  foreign  materials. 

VII.     CHEMICAL  ANALYSIS. 

Loss  ON  IGNITION. 

20.  One  gram  of  cement  shall  be  heated  in  a  weighed  cov-  Method, 
ered  platinum  crucible,   of  20  to  25-cc.   capacity,   as  follows, 
using  either  method  (a)  or  (b)  as  ordered: 

(a)  The  crucible  shall  be  placed  in  a  hole  in  an  asbestos 
board,  clamped  horizontally  so  that  about  three-fifths  of  the 
crucible  projects  below,  and  blasted  at  a  full  red  heat  for  15 
minutes  with  an  inclined  flame;    the  loss  in  weight  shall  be 
checked  by  a  second  blasting  for  5  minutes.      Care  shall  be 
taken  to  wipe  off  particles  of  asbestos  that  may  adhere  to  the 
crucible  when  withdrawn  from  the  hole  in  the  board.     Greater 
neatness  and  shortening  of  the  time  of  heating  are  secured  by 
making  a  hole  to  fit  the  crucible  in  a  circular  disk  of  sheet  plat- 
inum and  placing  this  disk  over  a  somewhat  larger  hole  in  an 
asbestos  board. 

(b)  The  crucible  shall  be  placed  in  a  muffle  at  any  tempera- 
ture between  900  and  1000°  C.  for  15  minutes  and  the  loss  in 
weight  shall  be  checked  by  a  second  heating  for  5  minutes. 

21.  A  permissible  variation  of  0.25  will  be  allowed,  and  all  Permissible 
results  in  excess  of  the  specified  limit  but  within  this  permissible  Variation- 

variation  shall  be  reported  as  4  per  cent. 

V^ 

INSOLUBLE  RESIDUE. 

22.  To  a  1-g.  sample  of  cement  shall  be  added  10  cc.  of  Method, 
water  and  5  cc.  of  concentrated  hydrochloric  acid;    the  liquid 

shall  be  warmed  until  effervescence  ceases.  The  solution  shall 
be  diluted  to  50  cc.  and  digested  on  a  steam  bath  or  hot  plate 
until  it  is  evident  that  decomposition  of.  the  cement  is  complete. 
The  residue  shall  be  filtered,  washed  with  cold  water,  and  the 
filter  paper  and  contents  digested  in  about  30  cc.  of  a  5-per-cent 
solution  of  sodium  carbonate,  the  liquid  being  held  at  a  temper-  » 
ature  just  short  of  boiling  for  15  minutes.  The  remaining 
residue  shall  be  filtered,  washed  with  cold  water,  then  with  a 
few  drops  of  hot  hydrochloric  acid,  1 : 9,  and  finally  with  hot 


6       SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT. 

water,  and  then  ignited  at  a  red  heat  and  weighed  as  the  insoluble 
residue. 

Permissible          23.  A  permissible  variation  of  0.15  will  be  allowed,  and  all 
on"     results  in  excess  of  the  specified  limit  but  within  this  permissible 
variation  shall  be  reported  as  0.85  per  cent. 

SULFURIC  ANHYDRIDE. 

Method.  24.  One  gram  of  the  cement  shall  be  dissolved  in  5  cc.  of 

concentrated  hydrochloric  acid  diluted  with  5  cc.  of  water,  with 
gentle  warming;  when  solution  is  complete  40  cc.  of  water 
shall  be  added,  the  solution  filtered,  and  the  residue  washed 
thoroughly  with  water.  The  solution  shall  be  diluted  to  250  cc., 
heated  to  boiling  and  10  cc.  of  a  hot  10-per-cent  solution  of 
barium  chloride  shall  be  added  slowly,  drop  by  drop,  from  a 
pipette  and  the  boiling  continued  until  the  precipitate  is  well 
formed.  The  solution  shall  be  digested  on  the  steam  bath  until 
the  precipitate  has  settled.  The  precipitate  shall  be  filtered, 
washed,  and  the  paper  and  contents  placed  in  a  weighed  plat- 
t  inum  crucible  and  the  paper  slowly  charred  and  consumed 
without  flaming.  The  barium  sulfate  shall  then  be  ignited  and 
weighed.  The  weight  obtained  multiplied  by  34.3  gives  the 
percentage  of  sulfuric  anhydride.  The  acid  filtrate  obtained  in 
the  determination  of  the  insoluble  residue  may  be  used  for  the 
estimation  of  sulfuric  anhydride  instead  of  using  a  separate 
sample. 

Permissible          25.  A  permissible  variation  of  0.10  will  be  allowed,  and  all 
Variation.     resuits  in  excess  of  the  specified  limit  but  within  this  permissible 
variation  shall  be  reported  as  2.00  per  cent. 

MAGNESIA. 

Method.  26.  To  0.5  g.  of  the  cement  in  an  evaporating  dish  shall 

be  added  10  cc.  of  water  to  prevent  lumping  and  then  10  cc.  of 
concentrated  hydrochloric  acid.      The  liquid  shall  be  gently 
!   heated  and  agitated  until  attack  is  complete.      The  solution 
shall  then  be  evaporated  to  complete  dryness  on  a  steam  or 
•    water  bath.     To  hasten  dehydration  the  residue  may  be  heated 
to  150  or  even  200°  C.  for  one-half  to  one  hour.     The  residue 
shall  be  treated  with  10  cc.  of  concentrated  hydrochloric  acid 
diluted  with  an  equal  amount  of  water.     The  dish  shall  be 


SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT.       7 

covered  and  the  solution  digested  for  ten  minutes  on  a  steam 
bath  or  water  bath.  The  diluted  solution  shall  be  filtered  and 
the  separated  silica  washed  thoroughly  with  water.1  Five  cubic 
centimeters  of  concentrated  hydrochloric  acid  and  sufficient 
bromine  water  to  precipitate  any  manganese  which  may  be 
present,  shall  be  added  to  the  filtrate  (about  250  cc.).  This 
shall  be  made  alkaline  with  ammonium  hydroxide,  boiled  until 
there  is  but  a  faint  odor  of  ammonia,  and  the  precipitated  iron 
and  aluminum  hydroxides,  after  settling,  shall  be  washed  with 
hot  water,  once  by  decantation  and  slightly  on  the  filter.  Set- 
ting aside  the  filtrate,  the  precipitate  shall  be  transferred  by  a 
jet  of  hot  water  to  the  precipitating  vessel  and  dissolved  in 
10  cc.  of  hot  hydrochloric  acid.  The  paper  shall  be  extracted 
with  acid,  the  solution  and  washings  being  added  to  the  main 
solution.  The  aluminum  and  iron  shall  then  be  reprecipitated 
at  boiling  heat  by  ammonium  hydroxide  and  bromine  water  in 
a  volume  of  about  100  cc.,  and  the  second  precipitate  shall  be 
collected  and  washed  on  the  filter  used  in  the  first  instance  if 
this  is  still  intact.  To  the  combined  filtrates  from  the  hydrox- 
ides of  iron  and  aluminum,  reduced  in  volume  if  need  be,  1  cc. 
of  ammonium  hydroxide  shall  be  added,  the  solution  brought 
to  boiling,  25  cc.  of  a  saturated  solution  of  boiling  ammonium 
oxalate  added,  and  the  boiling  continued  until  the  precipitated 
calcium  oxalate  has  assumed  a  well-defined  granular  form. 
The  precipitate  after  one  hour  shall  be  filtered  and  washed,  then 
with  the  filter  shall  be  placed  wet  in  a  platinum  crucible,  and 
the  paper  burned  off  over  a  small  flame  of  a  Bunsen  burner; 
after  ignition  it  shall  be  redissolved  in  hydrochloric  acid  and  the 
solution  diluted  to  100  cc.  Ammonia  shall  be  added  in  slight 
excess,  and  the  liquid  boiled.  The  lime  shall  then  be  reprecipi- 
tated by  ammonium  oxalate,  allowed  to  stand  until  settled, 
filtered  and  washed.  The  combined  filtrates  from  the  calcium 
precipitates  shall  be  acidified  with  hydrochloric  acid,  concen- 
trated on  the  steam  bath  to  about  150  cc.,  and  made  slightly 
alkaline  with  ammonium  hydroxide,  boiled  and  filtered  (to 
remove  a  little  aluminum  and  iron  and  perhaps  calcium) .  When 
cool,  10  cc.  of  saturated  solution  of  sodium-ammonium-hydrogen 
phosphate  shall  be  added  with  constant  stirring.  When  the 

1  Since  this  procedure  does  not  involve  the  determination  of  silica,  a  second  evaporation 
is'unnecessary. 


8       SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT. 

crystallin  ammonium-magnesium  orthophosphate  has  formed, 
ammonia  shall  be  added  in  moderate  excess.  The  solution  shall 
be  set  aside  for  several  hours  in  a  cool  place,  filtered  and  washed 
with  water  containing  2.5  per  cent  of  NH3.  The  precipitate 
shall  be  dissolved  in  a  small  quantity  of  hot  hydrochloric  acid, 
the  solution  diluted  to  about  100  cc.,  1  cc.  of  a  saturated  solu- 
tion of  sodium-ammonium-hydrogen  phosphate  added,  and 
ammonia  drop  by  drop,  with  constant  stirring,  until  the  pre- 
cipitate is  again  formed  as  described  and  the  ammonia  is  in 
moderate  excess.  The  precipitate  shall  then  be  allowed  to  stand 
about  two  hours,  filtered  and  washed  as  before.  The  paper 
and  contents  shall  be  placed  in  a  weighed  platinum  crucible, 
the  paper  slowly  charred,  and  the  resulting  carbon  carefully 
burned  off.  The  precipitate  shall  then  be  ignited  to  constant 
weight  over  a  Meker  burner,  or  a  blast  not  strong  enough  to 
soften  or  melt  the  pyrophosphate.  The  weight  of  magnesium 
pyrophosphate  obtained  multiplied  by  72.5  gives  the  percentage 
of  magnesia.  The  precipitate  so  obtained  always  contains  some 
calcium  and  usually  small  quantities  of  iron,  aluminum,  and 
manganese  as  phosphates. 

Permissible  27.  A  permissible  variation  of  0.4  will  be  allowed,  and  all 
results  in  excess  of  the  specified  limit  but  within  this  permissible 
variation  shall  be  reported  as  5.00  per  cent. 


Variation. 


VIII.     DETERMINATION   OF   SPECIFIC   GRAVITY. 

Apparatus.  28.  The  determination  of  specific  gravity  shall  be  made 

with  a  standardized  Le  Chatelier  apparatus  which  conforms  to 
the  requirements  illustrated  in  Fig.  1.  This  apparatus  is  stand- 
ardized by  the  United  States  Bureau  of  Standards.  Kerosene 
free  from  water,  or  benzine  not  lighter  than  62°  Baume,  shall 
be  used  in  making  this  determination. 

Method.  29.  The  flask  shall  be  filled  with  either  of  these  liquids- to 

a  point  on  the  stem  between  zero  and  one  cubic  centimeter, 
and  64  g.  of  cement,  of  the  same  temperature  as  the  liquid, 
shall  be  slowly  introduced,  taking  care  that  the  cement  does 
not  adhere  to  the  inside  of  the  flask  above  the  liquid  and  to 
free  the  cement  from  air  by  rolling  the  flask  in  an  inclined 
position.  After  all  the  cement  is  introduced,  the  level  of  the 
liquid  will  rise  to  some  division  of  the  graduated  neck;  the 


SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT.       9 


(•- 5cm 


ljNo|.A|J 


Ground  Glass 
Stopper-'' 


c!c 


v \ 


6cc 


Have  two  O.I  cc 
Graduations  extend 
above  J and 

below  0  Mark  --—-•-.> 


17  cc 


8  cm 


-H  i 

[<- -—  9cm >) 

FIG.  1. — Le  Chatelier  Apparatus, 


.  S 


10     SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT. 

difference  between  readings  is  the  volume  displaced  by  64  g. 
of  the  cement. 

The  specific  gravity  shall  then  be  obtained  from  the  formula 

Weight  of  cement  (g.) 

Specific  gravity  = — 

Displaced  volume  (cc.) 

30.  The  flask,  during  the  operation,  shall  be  kept  immersed 
in  water,  in  order  to  avoid  variations  in  the  temperature  of 
the  liquid  in  the  flask,  which  shall  not  exceed  0°.5  C.     The 
results  of  repeated  tests  should  agree  within  0.01. 

31.  The  determination  of  specific  gravity  shall  be  made  on 
the  cement  as  received;   if  it  falls  below  3.10,  a  second  deter- 
mination shall  be  made  after  igniting  the  sample  as  described 
in  Section  20. 

IX.     DETERMINATION   OF   FINENESS. 

Apparatus.  32.  Wire  cloth  for  standard  sieves  for  cement  shall  be 
woven  (not  twilled)  from  brass,  bronze,  or  other  suitable  wire, 
and  mounted  without  distortion  on  frames  not  less  than  lj  in. 
below  the  top  of  the  frame.  The  sieve  frames  shall  be  circular, 
approximately  8  in.  in  diameter,  and  may  be  provided  with  a 
pan  and  cover. 

33.  A  standard  No.  200  sieve  is  one  having  nominally  an 
0.0029-in.  opening  and  200  wires  per  inch  standardized  by  the 
U.  S.  Bureau  of  Standards,  and  conforming  to  the  following 
requirements: 

The  No.  200  sieve  should  have  200  wires  per  inch,  and  the 
number  of  wires  in  any  whole  inch  shall  not  be  outside  the 
limits  of  192  to  208.  No  opening  between  adjacent  parallel 
wires  shall  be  more  than  0.0050  in.  in  width.  The  diameter  of 
the  wire  should  be  0.0021  in.  and  the  average  diameter  shall  not 
be  outside  the  limits  0.0019  to  0.0023  in.  The  value  of  the 
sieve  as  determined  by  sieving  tests  made  in  conformity  with 
the  standard  specification  for  these  tests  on  a  standardized 
cement  which  gives  a  residue  of  25  to  20  per  cent  on  the 
No.  200  sieve,  or  on  other  similarly  graded  material,  shall  not 
show  a  variation  of  more  than  1.5  per  cent  above  or  below  the 
standards  maintained  at  the  Bureau  of  Standards. 

Method.  34.  The  test  shall  be  made  with  50  g.  of  cement.     The 

sieve  shall  be  thoroughly  clean  and  dry.     The  cement  shall  be 


SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT.      11 

placed  on  the  No.  200  sieve,  with  pan  and  cover  attached,  if 
desired,  and  shall  be  held  in  one  hand  in  a  slightly  inclined  posi- 
tion so  that  the  sample  will  be  well  distributed  over  the  sieve, 
at  the  same  time  gently  striking  the  side  about  150  times  per 
minute  against  the  palm  of  the  other  hand  on  the  up  stroke. 
The  sieve  shall  be  turned  every  20  strokes  about  one-sixth  of  a 
revolution  in  the  same  direction.  The  operation  shall  continue 
until  not  more  than  0.05  g.  passes  through  in  one  minute  of 
continuous  sieving.  The  fineness  shall  be  determined  from  the 
weight  of  the  residue  on  the  sieve  expressed  as  a  percentage  of 
the  weight  of  the  original  sample. 

35.  Mechanical  sieving  devices  may  be  used,  but  the  cement 
shall  not  be  rejected  if  it  meets  the  fineness  requirement  when 
tested  by  the  hand  method  described  in  Section  34. 

36.  A  permissible  variation  of  1  will  be  allowed,  and  all  Permissible 
results  in  excess  of  the  specified  limit  but  within  this  permissible  Vanatlon- 
variation  shall  be  reported  as  22  per  cent. 

X.     MIXING  CEMENT   PASTES  AND   MORTARS. 

37.  The  quantity  of  dry  material  to  be  mixed  at  one  time  Method, 
shall  not  exceed  1000  g.  nor  be  less  than  500  g.     The  propor- 
tions of  cement  or  cement  and  sand  shall  be  stated  by  weight  in 
grams  of  the  dry  materials;    the  quantity  of  water  shall  be 
expressed  in  cubic  centimeters  (l  cc.  of  water  =  1  g.).     The  dry 
materials  shall  be  weighed,  placed  upon  a  non-absorbent  surface, 
thoroughly  mixed  dry  if  sand  is  used,  and  a  crater  formed  in 

the  center,  into  which  the  proper  percentage  of  clean  water  shall 
be  poured;  the  material  on  the  outer  edge  shall  be  turned  into 
the  crater  by  the  aid  of  a  trowel.  After  an  interval  of  J  minute 
for  the  absorption  of  the  water  the  operation  shall  be  completed 
by  continuous,  vigorous  mixing,  squeezing  and  kneading  with 
the  hands  for  at  least  one  minute.1  During  the  operation  of 
mixing,  the  hands  should  be  protected  by  rubber  gloves. 

38.  The  temperature  of  the  room  and  the  mixing  water  \ 
shall  be  maintained  as  nearly  as  practicable  at  21°  C.  (70°  F.). 

1  In  order  to  secure  uniformity  in  the  results  of  tests  for  the  time  of  setting  and  tensile 
strength  the  manner  of  mixing  above  described  should  be  carefully  followed.  At  least  one 
minute  is  necessary  to  obtain  the  desired  plasticity  which  is  not  appreciably  affected  by  con- 
tinuing the  mixing  for  several  minutes.  The  exact  time  necessary  is  dependent  upon  the 
personal  equation  of  the  operator.  The  error  in  mixing  should  be  on  the  side  of  over  mixing. 


12     SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT. 

XL     NORMAL  CONSISTENCY. 

Apparatus.  39.  The  Vicat  apparatus  consists  of  a  frame  A  (Fig.  2) 
bearing  a  movable  rod  B,  weighing  300  g.,  one  end  C  being 
1  cm.  in  diameter  for  a  distance  of  6  cm.,  the  other  having  a 
removable  needle  Z),  1  mm.  in  diameter,  6  cm.  long.  The  rod 


FIG.  2. — Vicat  Apparatus. 


Is  reversible,  and  can  be  held  in  any  desired  position  by  a  screw 
E,  and  has  midway  between  the  ends  a  mark  F  which  moves 
under  a  scale  (graduated  to  millimeters)  attached  to  the  frame  A . 
The  paste  is  held  in  a  conical,  hard-rubber  ring  G,  7  cm;  in  diam- 
eter at  the  base,  4  cm.  high,  resting  on  a  glass  plate  H  about 
10  cm.  square. 


SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT.      13 

40.  In  making  the  determination,  500  g.  of  cement,  with  a  Method, 
measured  quantity  of  water,  shall  be  kneaded  into  a  paste,  as 
described  in  Section  37,  and  quickly  formed  into  a  ball  with 
the  hands,  completing  the  operation  by  tossing  it  six  times  from 
one  hand  to  the  other,  maintained  about  6  in.  apart;  the  ball 
resting  in  the  palm  of  one  hand  shall  be  pressed  into  the  larger 
end  of  the  rubber  ring  held  in  the  other  hand,  completely  filling 
the  ring  with  paste;  the  excess  at  the  larger  end  shall  then  be 
removed  by  a  single  movement  of  the  palm  of  the  hand;  the 
ring  shall  then  be  placed  on  its  larger  end  on  a  glass  plate  and 
the  excess  paste  at  the  smaller  end  sliced  off  at  the  top  of  the 
ring  by  a  single  oblique  stroke  of  a  trowel  held  at  a  slight  angle 

TABLE  I. — PERCENTAGE  OF  WATER  FOR  STANDARD  MORTARS. 


Percentage  of  Water 
for  Neat  Cement 
Paste  of  Normal 
Consistency 

Percentage  of  Water 
for  One  Cement, 
Three  Standard  Ottawa 
Sand. 

Percentage  of  Water 
for  Neat  Cement 
Paste  of  Normal 
Consistency. 

Percentage  of  Water 
for  One  Cement, 
Three  Standard  Ottawa 
Sand. 

15 

9.0 

23 

10.3 

16 

9.2 

24 

10.5 

17 

18 
19 

9.3 
9.5 

9.7 

25 
26 
27 

10.7 
10.8 
11.0 

20 

9.8 

28 

11.2 

21 

22 

10.0 
10.2 

29 
30 

11.3 
11.5 

with  the  top  of  the  ring.  During  these  operations  care  shall  be 
taken  not  to  compress  the  paste.  The  paste  confined  in  the 
ring,  resting  on  the  plate,  shall  be  placed  under  the  rod,  the 
larger  end  of  which  shall  be  brought  in  contact  with  the  surface 
of  the  paste;  the  scale  shall  be  then  read,  and  the  rod  quickly 
released.  The  paste  shall  be  of  normal  consistency  when  the 
rod  settles  to  a  point  10  mm.  below  the  original  surface  in 
\  minute  after  being  released.  The  apparatus  shall  be  free 
from  all  vibrations  during  the  test.  Trial  pastes  shall  be  made 
with  varying  percentages  of  water  until  the  normal  consistency 
is  obtained.  The  amount  of  water  required  shall  be  expressed 
in  percentage  by  weight  of  the  dry  cement. 

41.  The  consistency  of  standard  mortar  shall  depend  on  the 


14     SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT. 

amount  of  water  required  to  produce  a  paste  of  normal  con- 
sistency from  the  same  sample  of  cement.  Having  determined 
the  normal  consistency  of  the  sample,  the  consistency  of  stand- 
ard mortar  made  from  the  same  sample  shall  be  as  indicated  in 
Table  I,  the  values  being  in  percentage  of  the  combined  dry 
weights  of  the  cement  and  standard  sand. 

XII.     DETERMINATION  OF  SOUNDNESS.1 

Apparatus.  42.  A  steam  apparatus,  which  can  be  maintained  at  a  tem- 
perature between  98  and  100°  C.,  or  one  similar  to  that  shown 
in  Fig.  3,  is  recommended.  The  capacity  of  this  apparatus  may 
be  increased  by  using  a  rack  for  holding  the  pats  in  a  vertical 
or  inclined  position. 

Method.  43.  A  pat  from  cement  paste  of  normal  consistency  about 

3  in.  in  diameter,  J  in.  thick  at  the  center,  and  tapering  to  a 
thin  edge,  shall  be  made  on  clean  glass  plates  about  4  in.  square, 
and  stored  in  moist  air  for  24  hours.  In  molding  the  pat,  the 
cement  paste  shall  first  be  flattened  on  the  glass  and  the  pat 
then  formed  by  drawing  the  trowel  from  the  outer  edge  toward 
the  center. 

44.  The  pat  shall  then  be  placed  in  an  atmosphere  of  steam 
at  a  temperature  between  98  and  100°  C.  upon  a  suitable  sup- 
port 1  in.  above  boiling  water  for  5  hours. 

45.  Should   the  pat  leave   the  plate,   distortion  may  be 
detected  best  with  a  straight  edge  applied  to  the  surface  which 
was  in  contact  with  the  plate. 

XIII.    DETERMINATION  OF  TIME  OF  SETTING. 

46.  The  following  are  alternate  methods,  either  of  which 
may  be  used  as  ordered: 

Vicat  47.  The  time  of  setting  shall  be  determined  with  the  Vicat 

Apparatus.  apparatus  described  in  Section  39.     (See  Fig.  2.) 
Vicat  48.  A  paste  of  normal  consistency  shall  be  molded  in  the 

Method,     hard-rubber  ring  G  as  described  in  Section  40,  and  placed  under 

1  Unsoundness  is  usually  manifested  by  change  in  volume  which  causes  distortion, 
cracking,  checking  or  disintegration. 

Pats  improperly  made  or  exposed  to  drying  may  develop  what  are  known  as  shrinkage 
cracks  within  the  first  24  hours  and  are  not  an  indication  of  unsoundness.  These  conditions 
are  illustrated  in  Fig.  4. 

The  failure  of  the  pats  to  remain  on  the  glass  or  the  cracking  of  the  glass  to  which  the 
pats  are  attached  does  not  necessarily  indicate  unsoundness. 


SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT.      15 


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16    SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT. 


SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT.      17 

the  rod  B,  the  smaller  end  of  which  shall  then  be  carefully 
brought  in  contact  with  the  surface  of  the  paste,  and  the  rod 
quickly  released.  The  initial  set  shall  be  said  to  have  occurred 
when  the  needle  ceases  to  pass  a  point  5  mm.  above  the  glass 
plate  in  J  minute  after  being  released;  and  the  final  set,  when 
the  needle  does  not  sink  visibly  into  the  paste.  The  test  pieces 


(a)  Pat  with  Top  Surface  Flattened  for  Determining 
Time  of  Setting  by  Gillmore  Method. 


(b)  Gillmore  Needles. 
FIG.  5. 

shall  be  kept  in  moist  air  during  the  test.  This  may  be  accom- 
plished by  placing  them  on  a  rack  over  water  contained  in  a 
pan  and  covered  by  a  damp  cloth,  kept  from  contact  with 
them  by  means  of  a  wire  screen;  or  they  may  be  stored  in  a 
moist  closet.  Care  shall  be  taken  to  keep  the  needle  clean,  as 
the  collection  of  cement  on  the  sides  of  the  needle  retards  the 


18      SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT. 


Gillmore 
Needles. 


penetration,  while  cement  on  the  point  may  increase  the  pene- 
tration. The  time  of  setting  is  affected  not  only  by  the  per- 
centage and  temperature  of  the  water  used  and  the  amount  of 
kneading  the  paste  receives,  but  by  the  temperature  and  humid- 
ity of  the  air,  and  its  determination  is  therefore  only  approximate. 
49.  The  time  of  setting  shall  be  determined  by  the  Gillmore 


. 

FIG.  6. — Details  for  Briquette. 

needles.     The  Gillmore  needles  should  preferably  be  mounted 
as  shown  in  Fig.  5  (&). 

Gillmore  50.  The  time  of  setting  shall  be  determined  as  follows: 
A  pat  of  neat  cement  paste  about  3  in.  in  diameter  and  £  in.  in 
thickness  with  a  flat  top  (Fig.  5  (a)),  mixed  to  a  normal  con- 
sistency, shall  be  kept  in  moist  air  at  a  temperature  maintained 


Method. 


SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT.      19 


as  nearly  as  practicable  at  21°  C.  (70°  F.).  The  cement  shall  be 
considered  to  have  acquired  its  initial  set  when  the  pat  will  bear, 
without  appreciable  indentation,  the  Gillmore  needle  TV  in.  in 
diameter,  loaded  to  weigh  J  Ib.  The  final  set  has  been  acquired 
when  the  pat  will  bear  without  appreciable  indentation,  the 
Gillmore  needle  -fa  in.  in  diameter,  loaded  to  weigh  1  Ib.  In 
making  the  test,  the  needles  shall  be  held  in  a  vertical  position, 
and  applied  lightly  to  the  surface  of  the  pat. 

XIV.     TENSION   TESTS. 

51.  The  form  of  test  piece  shown  in  Fig.  6  shall  be  used.  Form  of  Test 
The  molds  shall  be  made  of  non-corroding  metal  and  have  suf-  Piece* 
ficient  material  in  the  sides  to  prevent  spreading  during  mold- 
ing.     Gang  molds  when  used  shall  be  of  the  type  shown  in 

Fig.  7.     Molds  shall  be  wiped  with  an  oily  cloth  before  using. 

52.  The  sand  to  be  used  shall  be  natural  sand  from  Ottawa,  standard  Sand. 


FIG.  7.— Gang  Mold. 

,  111.,  screened  to  pass  a  No.  20  sieve  and  retained  on  a  No.  30 
sieve.  This  sand  may  be  obtained  from  the  Ottawa  Silica  Co., 
at  a  cost  of  two  cents  per  pound,  f.  o.  b.  cars,  Ottawa,  111. 

53.  This  sand,  having  passed  the  No.  20  sieve,  shall  be  con- 
sidered standard  when  not  more  than  5  g.  pass  the  No.  30  sieve 
after  one  minute  continuous  sieving  of  a  500-g.  sample. 

54.  The  sieves  shall  conform  to  the  following  specifications: 
The  No.  20  sieve  shall  have  between  19.5    and  20.5  wires 

per  whole  inch  of  the  warp  wires  and  between  19  and  21  wires 
per  whole  inch  of  the  shoot  wires.  The  diameter  of  the  wire 
should  be  0.0165  in.  and  the  average  diameter  shall  not  be 
outside  the  limits  of  0.0160  and  0.0170  in. 

The  No.  30  sieve  shall  have  between  29.5  and  30.5  wires 
per  whole  inch  of  the  warp  wires  and  between  28.5  and  31.5 
wires  per  whole  inch  of  the  shoot  wires.  The  diameter  of  the 
wire  should  be  0.0110  in.  and  the  average  diameter  shall  not 
be  outside  the  limits  0.0105  to  0.0115  in. 


20      SPECIFICATIONS  AND  TESTS  FOR  PORTLAND  CEMENT. 

Molding.  55.  Immediately  after  mixing,  the  standard  mortar  shall 

be  placed  in  the  molds,  pressed  in  firmly  with  the  thumbs  and 
smoothed  off  with  a  trowel  without  ramming.  Additional  mor-| 
tar  shall  be  heaped  above  the  mold  and  smoothed  off  with 
trowel;  the  trowel  shall  be  drawn  over  the  mold  in  such  a  man-l 
ner  as  to  exert  a  moderate  pressure  on  the  material.  The  mold 
shall  then  be  turned  over  and  the  operation  of  heaping,  thumb-] 
ing  and  smoothing  off  repeated. 

Testing.  56.  Tests  shall  be  made  with  any  standard  machine.     Th< 

briquettes  shall  be  tested  as  soon  as  they  are  removed  from  the] 
water.     The  bearing  surfaces  of  the  clips  and  briquettes  shall] 
be  free  from  grains  of  sand  or  dirt.     The  briquettes  shall  b< 
carefully  centered  and  the  load  applied  continuously  at  the  ral 
of  600  Ib.  per  minute. 

57.  Testing  machines  should  be  frequently  calibrated  ii 
order  to  determine  their  accuracy. 

Faulty  58.  Briquettes  that  are  manifestly  faulty,  or  which  giv< 

'es*  strengths  differing  more  than  15  per  cent  from  the  average  valu 

of  all  test  pieces  made  from  the  same  sample  and  broken  a 

the  same  period,  shall  not  be  considered  in  determining  the 

tensile  strength. 

XV.     STORAGE   OF  TEST  PIECES. 
Apparatus.  59.  The  moist  closet  may  consist  of  a  soapstone,  slate  01 

concrete  box,  or  a  wooden  box  lined  with  metal.     If  a  woodei 
box  is  used,  the  interior  should  be  covered  with  felt  or  brc 
/'wicking  kept  wet.     The  bottom  of  the  moist  closet  should  be! 
.  covered  with  water.     The  interior  of  the  closet  should  be  pro- 
vided with  non-absorbent  shelves  on  which  to  place  the  test! 
pieces,  the  shelves  being  so  arranged  that  they  may  be  with-] 
drawn  readily. 

Methods.  60.  Unless  otherwise  specified  all  test  pieces,  immediate!] 

I  after  molding,  shall  be  placed  in  the  moist  closet  for  from  20  t< 

24  hours. 

61.  The  briquettes  shall  be  kept  in  molds  on  glass  platesj 
in  the  moist  closet  for  at  least  20  hours.     After  24  hours  in 
moist  air  the  briquettes  shall  be  immersed  in  clean  water  in| 
storage  tanks  of  non-corroding  material. 

62.  The  air  and  water  shall  be  maintained  as  nearly  as| 
practicable  at  a  temperature  of  21°  C.  (70°  F.). 


•BH  'Makers 


e 

Syracuse 


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